Fluid dispensing pump with sealing means



April 7, 1964 D. F. CORSETTE ETAL 3,128,018

FLUID DISPENSING PUMP WITH SEALING MEANS 2 ets-Sheet 1 Filed July 7, 1

INVENTOR5 Y azwr ezz JZ'ez' 61 aka a BY wasm'ca-ezl 1' waficm ATTORNEY;

April 7, 1964 D. F. CORSETTE ETAL 3,128,018

FLUID DISPENSING PUMP WITH SEALING MEANS Filed July 7. 1961 2 Sheets-Sheet 2 INVENTORS Iazyhsl Car-seize flex 6'. 'ao vrziez;

BY 3 14. ca'f. @Mlwdfi l a/a'ism ATTORNEYS United States Patent 3,128,018 FLUID DIShENEING PUMP WITH SEALING MEANS Dougias F. (Iorsette, Los Angeles, and Rex C. Cooprider,

Downey, Calii, assignors to The Brackett Company, Cincinnati, @hio, a corporation of Ohio Filed .Iuiy 7, 1961, Ser. No. 122,535

12 (Ziaims. (811i. 222--32ll) This invention relates to new and improved dispensers of the reciprocating piston type for discharging liquids from portable containers, either as a stream or as a fine spray or mist.

It has long been the practice to employ, for the dispensing of liquids from small containers, hand actuated pumps formed of moldable plastic material comprising, in assembled relation, a stationary unit for direct association with the container, and a reciprocable piston unit which is manipulated to effect discharge of the container contents. Each of these units is customarily made of a considerable number of separately formed plastic parts, adhesively secured or bonded together, for instance by a plastic solvent. The separate formation of these various parts and their assembly to form each of the two basic units of the pump is necessarily time consuming and expensive. Furthermore, the bonding of the parts is not invariably perfect, with the result that a significant proportion of the pumps so made are defective.

It is an object of the invention to effect substantial simplification of the pumps and of the method of making and assembling the same through initial molding or casting of each of the units, stationary and reciprocable, as a single integral structure, whereby the time consuming and expensive operation of manufl assembling of the five or six parts heretofore required in the production of each unit, and the bonding of these parts to form a unitary structure, are eliminated. In the preferred practice of the invention the two units, each integrally molded, are assembled and mounted on the container by relatively simple operations involving minor deformation of certain portions of the stationary unit. It is a feature of the invention that these operations are facilitated and made more certain and precise by structural modifications of both units, hereinafter described is detail.

It is also a feature of the invention to provide, in dispensers of the character described having stationary and reciprocable units, means whereby these units may be temporarily locked against relative displacement in a position such that the dispenser is completely sealed, thereby preventing leakage of liquid from the container during shipping, even though the container be inverted.

More specifically, it is an object of the invention to provide a liquid dispenser in which the reciprocable unit may be temporarily locked to the stationary unit to immobilize the former, in conjunction with novel sealing means acting, when the reciprocable unit is so immobilized, to prevent leakage of liquid from the container either through the normal liquid discharge passages or externally of the piston plunger.

Further objects and features of the invention will be apparent from the following description, taken in connection with the accompanying drawings, in which FIGURE 1 is a vertical sectional view of a dispenser embodying the principles of the invention, showing the unit in locked and sealed position for application to a container prior to shipment;

FIGURE 2 is a fragmentary enlarged sectional view of a part of the structure shown in FIGURE 1;

FIGURE 3 is a side elevation of a portion of the unit shown in FIGURE 1, with the parts in locked and sealed position;

FIGURE 4 is a vertical sectional view of the dispenser "ice without the head portion, illustrating the method of assembly by deformation of certain parts; and

FIGURE 5 is a fragmentary sectional view of sealing means, rendered effective on immobilization of the reciprocable unit,

To promote an understanding of the invention, reference will now be made to the preferred embodiment thereof illustrated in the accompanying drawings, and specific language will be used to describe the same. It will nevertheless be appreciated that no limitation of the scope of the invention is thereby intended, such further modifications and alterations being contemplated as would normally occur to one skilled in the art to which the invention relates.

Referring first to FIGURE 1, in which is illustrated an assembled unit, locked in the sealed position for shipping, it will be seen that the stationary unit of the dispenser comprises a cylindrical barrel 12, 21 depending suction tube 13, and a collar portion 14-. The collar portion 14 is formed at the upper end of barrel I2, noting that throughout the following description the dispenser will be assumed to occupy the upright position in which it is normally used. Elements 12, i3 and 14 are molded or cast integrally, this being made possible by the contour of the structure, which lends itself well to a single injection molding operation.

The upper end of the barrel 12 is preferably slotted at circumferentially spaced points as indicated at 18 for the purpose of preventing the formation of an airlock in the barrel 12 above the piston, to permit ingress to the container of air in order to replace discharged liquid, and to allow drainage into the container of liquid which may pass the piston and which would otherwise be trapped in the upper portion of barrel 12.

An annular flange 20, formed on the collar portion 14, provides a seat for container cap 21. Cap 21 is apertured to receive collar portion 14 and is internally threaded as shown at 22 for cooperative engagement with external threads formed on the neck of the container.

In lieu of the conventional gasket normally fitted beneath the collar and engaging the lip of the container neck to effect a seal, collar 14 is formed to provide an integral sealing portion. This preferably comprises an annular, downwardly facing V-shaped groove 75 formed in the lower edge of the collar, so dimensioned as to receive therein the annular lip of the container neck. The collar is further formed, inwardly of groove 75, to provide an annular recess 76, whereby both the outer and inner walls defining groove 75 may flex more readily. Usually, each wall will be flexed inwardly slightly below the upper surface of the lip to grip and more effectively seal the container neck as the collar is forced downwardly on the latter in threading the container cap down. However, depending on the shape of the lip, the walls defining groove 75 may be forced apart by the lip. It will be appreciated that despite wide manufacturing tolerances normally observed in the production of containers of glass and like material, the flexibility of the integral collar seal, formed as described, permits consistently effective sealing engagement with the lip of the container neck.

The collar portion 14 is further provided at its upper end with an interiorly threaded portion 25 of reduced diameter, forming a shoulder 26 which is subject to deformation for the purpose of locking the container cap 21 on the collar portion 14. Thus downward pressure exerted against shoulder 26, for instance by means of a cylindrical tool embracing the upper end of collar portion 14, deforms or swages collar portion 14 sufiiciently to form thereon an annular lip 30 overlying container cap 21, whereby the cap 21 is held on collar portion 14 against displacement, but is rotatable thereon to permit threading of the cap 21 on the container neck.

The stationary and reciprocable units of the dispenser may be formed of any moldable plastic materials, preferably materials commonly designated thermoplastics, such as the polyolefins, and especially polypropylene. Excellent results are achieved by the use of a linear polyethylene sold under the trademark Super Dylan by Koppers Company, Inc., of Pittsburgh, Pennsylvania. In general, any plastic material subject to hot or cold flow, capable of being molded and readily deformed after molding in response to heat and/ or pressure may be employed.

The reciprocable unit of the dispenser consists essentially of a plunger 35, and a depending hollow piston 36, dimensioned to fit snugly within the interior wall of barrel 12, these elements being integrally formed. A head portion 37 and a discharge spout 38, also integrally molded, are fitted on the upper end of the plunger 35, as hereinafter described, the upper part of the head portion being formed to provide the usual finger piece 39 for depressing the reciprocable unit to pump liquid from the container.

Discharge passage 40, extending upwardly through the plunger 35 and head portion 37, communicates at its upper end with a passage 41 in the discharge spout 38, the spout being molded or cast in the form of a straight tube, and being subsequently deformed by pressure, if desired, so that its outer end is inclined downwardly as shown.

Depending within and from the upper end of plunger 35 is a valve seat, having a thin walled cylindrical or tubular portion 44 and a downwardly tapering portion 48 in which ball valve 45 is received, preferably as shown in FIGURE 1. Because of the flexibility of the valve seat, the ball is fully accommodated to provide an eflicient seal despite deformation of the thicker and less flexible wall of plunger 35, occurring occasionally as the result of unequal cooling or in the process of withdrawing the spout from the mold, as described in application Serial No. 23,469, filed April 20, 1960, now Patent No. 3,064,310, in the name of Rex C. Cooprider. Stud 47, depending from and within head portion 37 serves as a retainer to limit displacement of valve ball 45 from its seat. It will be appreciated that valve ball 45 functions in the usual manner as a one-way valve to permit flow of liquid in an upward direction only in passage 40, but functions more efl'eetively because of the unique construction of its seat.

Received within piston 36 and seated against the lower end of barrel 12 is a coil compression spring 52, acting to urge the reciprocable unit upwardly. Ball valve 55, seating by gravity in the lower end of barrel 12, acts as a check valve to prevent drainage of liquid downwardly from the barrel 12. Preferably the seat 53 for ball valve 55 forms an angle of at least 45 with the axis of the dispenser to minimize the possibility of wedging of the valve in its seat; this may cause a tendency of the valve to rattle on the upward stroke of the reciprocable unit. However, annular lip 56, extending upwardly from seat 53 and having slight clearance with ball valve 55, functions to prevent such rattling.

Spring 52 is formed with a convolution 60 of reduced diameter, preferably adjacent each end, as shown, to provide reversibility. As will be apparent from FIGURE 1 of the drawing, when the reciprocable unit is fully depressed, the ball valve 55 is engaged by the adjacent small convolution 60 of spring 52 to seat the valve against displacement, thus preventing flow of liquid past the valve and outwardly through passage 40 when the dispenser is inverted.

The reciprocable unit is retained in the depressed posi tion by coacting threads 61, 62 formed on the collar 14 and the head 37, respectively. When the head is screwed down within the collar, coacting sealing surfaces on the head and the collar are pressed together to prevent discharge of liquid from the container externally of the plunger 35. Thus the container is completely sealed and loss of liquid is prevented during handling and shipping,

l; this being of particular importance when toxic liquids such as insecticides are used.

The head to collar seal effected, when the plunger is fully depressed and locked by threading the head within the collar as above described, is of a unique type, and is shown in the enlarged fragmentary sectional view, FIG- URE 2. Thus the skirt portion of the head 37 is formed to provide a depending annular flange 73 having a pcripheral head 79 and a depending lip 84 When the plunger is fully depressed as shown in FIGURES 1 and 2, the lip 80 engages an inclined annular surface 82 formed on collar 14, so that as the bead is pressed downwardly, the inclined surface 32 tends to expand circumferentially the lip 80 and thereby to press the bead 79 against the wall 83 of collar 14, thereby effecting a tight and eflicient seal. Since the flange '78 is fairly thin, achieved by forming an annular recess '77 immediately within the flange, the latter is sufliciently resilient to permit an interference fit within the collar. In other words, the outer diameter of the flange, at bead 79, may be slightly greater than the collar surface 83 within which the flange 78 is received in the sealing position of the dis penser components, thereby increasing sealing efliciency. Since the flange is resilient, however, the torque required to thread down and to release the head is quite low. Also, the radial pressure exerted by the flange 73, tending to expand collar 14, is reduced, minimizing the tendency of threads 61 to jump or strip as the head is threaded down.

In order that the head 37 may be threaded down tightly within the collar 14, a novel support for the collar is provided, shown more particularly in FIGURE 3 of the drawing. Thus the lower skirt 85 of the collar is serrated to provide teeth 86, each tooth having at each side thereof a surface 87 which is substantially parallel to the axis of the unit and surfaces 88 which are inclined with respect to the unit axis. A support or jig for the collar, which may comprise an annular sleeve (not shown) having a correspondingly serrated portion at its upper edge, engages and interlocks with the teeth 86 on the collar. Those edge surfaces of the coacting teeth on the collar and jig which are parallel to the unit axis resist rotation of the collar as the head is threaded down, without tending to force the collar upwardly and away from the jig. The inclined surfaces resist downward thrust, especially during deformation of the plunger guide. By pointing the tooth ends on the collar and jig, improper orientation in assembling the unit in the jig is avoided.

As hereinbefore indicated, collar portion 14 is deformed or swaged outwardly to form thereon an annular lip 30 overlying and retaining in position the container cap 21. The upper end of the barrel 12 is also deformed or swaged inwardly to provide a bearing or guide for the plunger 35 and to limit the upward stroke of the plunger and prevent its withdrawal from the stationary unit. These swaging operations may be conducted concurrently, if desired.

In FIGURE 4 the plunger 35 is shown assembled in the stationary unit in a depressed position and prior to the application of the head to the plunger, in which position both swaging operations may readily be performed. It will be noted that in FIGURE 4 the shoulder 26 is shown prior to deformation, in contrast to FIGURE 1 which illustrates the lip 30 provided by deforming the shoulder upon the application to the shoulder of downward pressure. Similarly, FIGURE 4 shows a shoulder 91 at the upper end of barrel 12 and adjacent the juncture of the barrel and the collar portion 14. Upon deformation of shoulder Q1 by the application of downward pressure, an annular lip or head d2, serving as a plunger guide and shown in its final form in FIGURE 1, is simply and accurately produced.

It will be noted that in the lowered position in which the plunger is shown in both FIGURES 1 and 4, the plunger guide 92 engages an enlarged portion 93 of the plunger, which serves to limit the inward flow of material during the swaging operation. The increase in outer diameter of the plunger at 93 is very slight, and is exaggerated in the drawing, being only sufiicient to insure that during the normal working stroke of the plunger there is adequate mechanical clearance between the plunger and the plunger guide 92, which maintains the plunger upright While permitting smooth reciprocal movement of the plunger in the guide. It will be appreciated that the necessary tolerance between plunger and guide may thereby be readily and uniformly established.

In FIGURE 4 of the drawing there are shown in dotand-dash lines two generally cylindrical swaging tools in position to effect the external swage at shoulder 26 of the collar 14 and the internal swage at the shoulder 91 at the upper end of barrel 12. However, a single tool may conveniently be employed, the active surfaces of the tool being suitably shaped to cause the swaged portions to assume a desired configuration, for instance the configuration shown in FIGURE 1 at 30 and 92 respectively. During the swaging operation the stationary unit is supported in a jig which coacts with lower skirt 85 of collar 14, as hereinbefore described, to resist the downward thrust applied by the swaging tool. The swaging tool employed to form the plunger guide 92 may also be provided with means to hold the plunger 35 in its lowered position against the action of spring 52 so that the enlarged portion 93 of the plunger 35 may function as described above.

The piston 36 is provided at its upper end with an outwardly flaring skirt or chevron 94, tending to resist flow of liquid downwardly in the annular passage between barrel 12 and plunger 35. However, it is found that when the dispenser is inverted or laid on its side, and pressure develops within the container, for example as the result of temperature rise, liquid trapped above the piston and within the said passage may be forced past the piston and into the discharge passage 40, resulting in leakage outwardly of the passage and through the spout 38. To prevent this, a special seal, rendered operative when the plunger is in its lowermost and immobilized position, is provided.

Thus, sealing means, which is preferably constructed as shown in FIGURE 5, essentially similar to the head to collar seal hereinbefore described, is provided at the lower end of the plunger. The lower skirt portion of piston 36 is formed to provide a peripheral head 95 and a depending lip 96. When the plunger is fully depressed as shown in FIGURES l and 5, the lip 96 engages an inclined annular surface 98 formed at the lower end of the barrel 12, tending to expand circumferentially the lip 96 and thereby to press the bead 95 outwardly against the barrel wall, efiecting a tight and eflicient seal. Since the skirt of the piston is fairly thin, it is sufficiently resilient to permit an interference fit within the barrel, thereby increasing sealing efficiency during normal operation of the plunger without, however, increasing materially the friction exerted by the piston against the cylinder wall. When the seal is fully engaged upon threading of the head skirt within the collar 14, egress of liquid from the passage between barrel 12 and plunger 35 into the discharge passage 40* is effectively prevented.

In the event it is desired to provide a dispenser capable of discharging liquid in the form of a mist or spray rather than in a stream, appropriate modification of the illustrated embodiment of the invention may be effected without difficulty in accordance with prior art teachings and practice. For instance, the head and spout illustrated herein may be replaced with a one-piece spray head fitted on the upper end of the plunger and formed as described in our pending application Serial No. 719,427, filed March 5, 1958, now Patent No. 3,075,708, entitled One Piece Aerosol Spray Head, the only modification required of the spray head therein disclosed being the formation of external threads thereon for engagement with the internal threads of the collar 14 as described herein.

The application of the invention to the conventional container cap, formed for threaded engagement with a container neck, is not intended as a limitation of the practice of the invention.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. In a fluid dispensing pump, the combination with a generally vertical cylindrical pump barrel having at its upper end a collar, of a plunger reciprocally disposed in said barrel and having at its upper end md above said collar a discharge head having a discharge orifice for fluid, spring means acting between said barrel and plunger for urging said plunger upwardly in said barrel, a check valve associated with said barrel to prevent downward movement of fluid therein, said plunger being formed to provide a discharge passage extending therethrough and communicating with said discharge orifice, means acting between said head and said collar to hold said head and plunger in a depressed and immobilized position against the action of said spring means, sealing means acting between said head and collar, said sealing means being rendered operative when said plunger is depressed and immobilized to seal said barrel to prevent leakage externally of said plunger, and means operable when said plunger is depressed and immobilized to seal said discharge passage to prevent leakage internally of said plunger, said last named means comprising coacting sealing surfaces relatively displaced into engagement to block flow of liquid through the discharge passage and hence to said orifice, said first named sealing means comprising a depending annular flange on said head having a peripheral bead thereon, a first surface on said collar engaged by said bead, and a second surface on said collar forming an acute angle with said first surface and engaging said flange when said head and plunger occupy said depressed and immobilized position to expand said flange and thereby to apply pressure between said bead and said first surface on said collar.

2. In a fluid dispensing pump, the combination with a generally vertical cylindrical pump barrel having at its upper end a collar having threads thereon, of a plunger reciprocally disposed in said barrel and having at its upper end and above said collar a discharge head having a discharge orifice for fluid, spring means acting between said barrel and plunger for urging said plunger upwardly in said barrel, a check valve associated with said barrel to prevent downward movement of fluid therein, said plunger being formed to provide a discharge passage extending therethrough and communicating with said discharge orifice, said discharge head having a portion threaded for engagement with the threads onsaid collar to hold said plunger in a depressed and immobilized position against the action of said spring means, sealing means acting between said head and collar, said sealing means being rendered operative when said plunger is depressed and immobilized to seal said barrel to prevent leakage externally of said plunger, and means operable when said plunger is depressed and immobilized to seal said discharge passage to prevent leakage internally of said plunger, said last named means comprising coacting sealing surfaces relatively displaced into engagement to block flow of liquid through the discharge passage and hence to said orifice, said first named sealing means comprising a depending annular flange on said head having a peripheral bead thereon, a first surface on said collar engaged by said bead, and a second surface on said collar forming an acute angle with said first surface and engaging said flange as said head is threaded down on said collar to expand said flange and thereby to apply pressure between said bead and said first surface on said collar.

3. .In a fluid dispensing pump, the combination with a generally vertical cylindrical pump barrel having at its upper end a collar, of a plunger reciprocally disposed in said barrel and having at its upper end and above said collar a discharge head having a discharge orifice for fluid and having at its lower end a piston slidably received within said barrel, spring means acting between said barrel and plunger for urging said plunger upwardly in said barrel, a check valve associated with said barrel to prevent downward movement of fluid therein, said plunger being formed to provide a discharge passage extending therethrough and communicating with said discharge orifice, means acting between said head and said collar to hold said head and plunger in a depressed and immobilized position against the action of said spring means, coacting sealing surfaces on said head and collar, said sealing surfaces being engaged when said plunger is depressed and immobilized to seal said barrel to prevent leakage externally of said plunger, means operable when said plunger is depressed and immobilized to seal said discharge passage to prevent leakage internally of said plunger, said last named means comprising coacting sealing surfaces relatively displaced into engagement to block flow of liquid through the discharge passage and hence to said orifice, land coacting sealing means on said piston and barrel engaged under pressure when said head and plunger occupy said depressed and immobilized position to prevent leakage past said piston.

4. The combination of claim 3 in which said sealing means on said piston and barrel comprise a depending annular lip on said piston having a peripheral bead thereon, a first surface on said barrel for engagement by said head, and a second surface on said barrel forming an acute angle with said first surface and engaging said piston lip in the depressed and immobilized position of said plunger to expand said lip and thereby to apply pressure between said bead and said first surface on said barrel.

5. In a fluid dispensing pump, the combination with a generally vertical cylindrical pump barrel having at its upper end a collar having threads thereon, of a plunger reciprocally disposed in said barrel and having at its upper end and above said collar a discharge head having a discharge orifice for fluid and having at its lower end a piston slidably received within said barrel, spring means acting between said barrel and plunger for urging said plunger upwardly in said barrel, a check valve associated with said barrel to prevent downward movement of fluid therein, said plunger being formed to provide a discharge passage extending therethrough and comunicating with said discharge orifice, said discharge head having a portion threaded for engagement with the threads on said collar to hold said plunger in a depressed and immobilized position against the action of said spring means, coacting sealing surfaces on said head and collar, said sealing sur faces being engaged when said plunger is depressed and immobilized to seal said barrel to prevent leakage externally of said plunger, means operable when said plunger is depressed and immobilized to seal said discharge passage to prevent leakage internally of said plunger, said last named means comprising coacting sealing surfaces relatively displaced into engagement to block flow of liquid through the discharge passage and hence to said orifice, and coacting sealing means on said piston and barrel engaged under pressure when said head and plunger occupy said depressed and immobilized position to prevent leakage past said piston, said last named sealing means comprising a depending annular flange on said piston having a peripheral bead thereon, a first surface on said barrel for engagement by said head, and a second surface on said barrel forming an acute angle with said first surface and engaging said piston flange in the depressed and immobilized position of said plunger to expand said flange and thereby to apply pressure between said head and said first surface on said barrel.

6. In a fluid dispensing pump, the combination with a generally vertical cylindrical pump barrel having at its upper end a collar, of a plunger reciprocally disposed in said barrel and having at its upper end and above said collar a discharge head having a discharge orifice for fluid, spring means acting between said barrel and plunger for urging said plunger upwardly in said barrel, a check valve associated with said barrel to prevent downward movement of fluid therein, said plunger being formed to provide a discharge passage extending therethrough and communicating with said discharge orifice, and a container cap seated on said collar and having threads for engaging the threads on a container neck, said collar being formed to provide an integral seal for engaging the lip of the container neck to seal the pump to the container, said seal comprising a pair of depending annular flanges having opposing conical faces defining an inverted V-shaped groove dimensioned for the reception of the container neck lip, said collar being further grooved inwardly of said flanges to permit fiexure of said flanges, whereby the latter may grip the container neck lip tightly when the container cap is threaded down despite variations in the dimensioning of said neck lip.

7. In a fluid dispensing pump, the combination with a generally vertical cylindrical pump barrel having at its upper end a collar, of a plunger reciprocally disposed in said barrel and having at its upper end and above said collar a discharge head having a discharge orifice for fluid, spring means acting between said barrel and plunger for urging said plunger upwardly in said barrel, a check valve associated with said barrel to prevent downward movement of fluid therein, said plunger being formed to provide a discharge passage extending therethrough and communicating with said discharge orifice, and check valve means in said plunger to prevent downward flow of fluid in said discharge passage, said last named valve means comprising a tubular member formed integrally with and depending within and from the upper end of the plunger, said member tapering downwardly adjacent its lower end to provide a valve seat, and a valve ball received on said seat, said tubular member having substantially less thickness than said barrel to provide for flexure of the member to accommodate said valve ball despite deformation of said barrel resulting from manufacturing stresses.

8. The combination of claim 7 in which the discharge head is provided with an axially disposed stud formed integrally with said head and depending into said tubular member into proximity to said valve ball to limit upward movement of the latter.

9. In a dispenser for discharging liquid from a container, the combination with a stationary unit comprising a cylindrical barrel and a collar portion at the upper end of said barrel, a cap for the container, said collar portion being dimensioned for insertion through an aperture in the container cap, means acting between said collar and said cap to lock the same against relative displacement longitudinally of said barrel, of a reciprocable unit comprising a plunger extending through said collar portion of said stationary unit, said plunger being of less external diameter than the internal diameter of said barrel and having at its lower end a piston slidably received in said cylindrical barrel and at its upper end a head portion providing a finger piece for manipulation of the plunger, said plunger, piston, and head portion having communicating passages extending therethrough for the discharge of fluid from said container on depression of said reciprocable unit, the upper end of said barrel being deformed by downward pressure after assembly of said plunger in said stationary unit to provide an inwardly directed part for engaging said plunger to afford a bearing for the latter and providing an abutment preventing withdrawal of said piston from said barrel, the outer diameter of the plunger being enlarged slightly adjacent the upper end of the plunger to provide a cylindrical surface against which the barrel is deformed to limit the ex tent of deformation and ensure a uniform and smooth working fit between the remainder of the plunger and the said inwardly directed part of the barrel.

10. In a dispenser for discharging liquid from a container, the combination with a stationary unit comprising a cylindrical barrel and a collar at the upper end of said barrel, of a reciprocable unit comprising a plunger extending through said collar, said plunger being of less external diameter than the internal diameter of said barrel and having at its lower end a piston slidably received in said cylindrical barrel and at its upper end a discharge head providing a finger piece for manipulation of the plunger, said plunger, piston, and discharge head having communicating passages extending therethrough for the discharge of fluid from said container on depression of said reciprocable unit, coacting threads on said discharge head and said collar for retaining said head and plunger in a depressed immobilized position when said head is threaded down on said collar, the upper end of said barrel being deformed by downward pressure after assembly of said plunger in said stationary unit to provide an inwardly directed part for engaging said plunger to afford a bearing for the latter and an abutment preventing withdrawal of said piston from said barrel, said barrel being formed to provide an annular peripherally arranged skirt having a serrated lower edge for engagement with a supporting jig during deformation of said barrel and threading of said head on said collar.

11. The combination of claim 10 in which the serrated edge on said barrel skirt is constituted by downwardly directed teeth of which certain first lateral surfaces are parallel to the barrel axis and certain second lateral surfaces are inclined to the barrel axis for coaction respectively with similarly disposed surfaces on said jig, whereby said first lateral surfaces resist rotation of said barrel during threading of said head on said collar and said second lateral surfaces resist downward thrust on said barrel during deformation of said barrel to provide said inwardly directed part.

12. The combination of claim 10 in which the serrated edge is constituted by downwardly directed teeth having pointed ends and forming a continuous toothed annulus for coaction with complementary upwardly directed teeth on said jig, whereby orientation of said barrel and jig are rendered unnecessary.

References Cited in the file of this patent UNITED STATES PATENTS 2,378,624 Edwards June 19, 1945 2,568,057 Cotter Sept. 18, 1951 2,861,839 Mellon Nov. 25, 1958 FOREIGN PATENTS 467,053 Canada Aug. 1, 1950 763,570 Great Britain Dec. 12, 1956 

1. IN A FLUID DISPENSING PUMP, THE COMBINATION WITH A GENERALLY VERTICAL CYLINDRICAL PUMP BARREL HAVING AT ITS UPPER END A COLLAR, OF A PLUNGER RECIPROCALLY DISPOSED IN SAID BARREL AND HAVING AT ITS UPPER END AND ABOVE SAID COLLAR A DISCHARGE HEAD HAVING A DISCHARGE ORIFICE FOR FLUID, SPRING MEANS ACTING BETWEEN SAID BARREL AND PLUNGER FOR URGING SAID PLUNGER UPWARDLY IN SAID BARREL, A CHECK VALVE ASSOCIATED WITH SAID BARREL TO PREVENT DOWNWARD MOVEMENT OF FLUID THEREIN, SAID PLUNGER BEING FORMED TO PROVIDE A DISCHARGE PASSAGE EXTENDING THERETHROUGH AND COMMUNICATING WITH SAID DISCHARGE OFRIFICE, MEANS ACTING BETWEEN SAID HEAD AND SAID COLLAR TO HOLD SAID HEAD AND PLUNGER IN A DEPRESSED AND IMMOBILIZED POSITION AGAINST THE ACTION OF SAID SPRING MEANS, SEALING MEANS ACTING BETWEEN SAID HEAD AND COLLAR, SAID SEALING MEANS BEING RENDERED OPERATIVE WHEN SAID PLUNGER IS DEPRESSED AND IMMOBILIZED TO SEAL SAID BARREL TO PREVENT LEAKAGE EXTERNALLY OF SAID PLUNGER, AND MEANS OPERABLE WHEN SAID PLUNGER IS DEPRESSED AND IMMOBILIZED TO SEAL SAID DISCHARGE PASSAGE TO PREVENT LEAKAGE INTERNALLY OF SAID PLUNGER, SAID LAST NAMED MEANS COMPRISING COACTING SEALING SURFACES RELATIVELY DISPLACED INTO ENGAGEMENT TO BLOCK FLOW OF LIQUID THROUGH THE DISCHARGE PASSAGE AND HENCE TO SAID ORIFICE, SAID FIRST NAMED SEALING MEANS COMPRISING A DEPENDING ANNULAR FLANGE ON SAID HEAD HAVING A PERIPHERAL BEAD THEREON, A FIRST SURFACE ON SAID COLLAR ENGAGED BY SAID BEAD, AND A SECOND SURFACE ON SAID COLLAR FORMING AN ACUTE ANGLE WITH SAID FIRST SURFACE AND ENGAGING SAID FLANGE WHEN SAID HEAD AND PLUNGER OCCUPY SAID DEPRESSED AND IMMOBILIZED POSITION TO EXPAND SAID FLANGE AND THEREBY TO APPLY PRESSURE BETWEEN SAID BEAD AND SAID FIRST SURFACE ON SAID COLLAR. 